Apparatus for cleaning condenser tubes



April 29, 1930.v

w. F. OBERHUBER APPARATUS FOR CLEANING CONDENSER TUBES Filed July 5. 1922 v ?atented Apr. 29 li3 QYQILLIAE F. OIBERHUBER, OF EAST LANSDOWNE, PENNSVANIA -APPARATUS FOR CLEANING CONDENSER TUBE$ Application filed July 3,

My invention relates to cleaning condenser tubes and to the slugs or plugs which are passed through the tubes to perform the cleaning operation.

A main purpose of myinvention is to progressively discharge fluid within the tube ahead of an advancing cleaner, slug or plug.

A further purpose is to expand the slug or plug into wiping contact with the interior of the tube by the driving fluid.

A further purpose is to permit limited passage of the driving fluid through the cleanmg slug or plug so as to insure ejection of the pug or slag if the tube becomes closed ahead 0 it.

A further purpose is to swell the rear portion of the slug during its passage through the tube by fluid pressure, contact with the interior of the tube and increasing the contact with .any slowing up of the slug or plug by reason of its engaging excessive dirt within the tube.

A further purpose is to provide a slug or plug with an aperture through it so that part of the fluid by which the slug or plug is driven passes through the plug or s ug. I

may ta er a central aperture so as to improve" the qua 1ty as a nozzle or may direct diagonally against the interior wall one or more streams to better break up the coating of dirt and separate it from the tube wall.

A further purpose is to combine the aperturing of the slug or plug with the expansion of the rear part orandbody of the slug so as to obtain both the flow through the slug upon which the success of my invention primarily depends and the outward swelling of the slug.

A further purpose is to give flexibility to the slug or plug and to the cupping at its rear.

A further purpose is to form a rearwardly facing cup upon the tube of the slug or plug and to support it by the body to prevent it from turning inside out.

Further purposes will appear in the specification and in the claims.

I have referred to illustrate my invention by a few orms only among many by which it may be presented, selecting forms which are practical, eficient and fully effective and maintaining it in tight 1922. Serial No. 572,570.

I which at the same time will illustrate the principles of my invention. f

Figure 1 is a perspective view showing one form of my invention. 1

Figure 2 is a reduced-scale longitudinal section of the device seen in Figure 1. Figure 3 is a perspective view showing a second form of my invention.

vFigure 4c is a reduced-scale longitudinal.

section of the device seen in F1 ure 3.

Figures 5 and 6 are centra longitudinal sections of other forms of my invention.

Figure 7 is a section of a condenser tube in which the slug of Figure 6 is shown.

Figure 8 is a top plan view of a slug carryingrmetal scrapers. 9 9igure 9 is a section of Figure 8 upon line Fi re 10 is a section similar to Figure 9 but 0 another form. v

In the drawings similar numerals indicate like parts.

It is desirable to clean condenser tubes nightly in order that the slime, sediment, etc., for convenience herein called dint, which has accumulated upon the inside of the tubes may be removed so that the efliciency (if heat transfer through the tubes may be maintained at a maximum. T

Though it is not new to pass plugs, known in the art as slugs, of resilient material, usual- 1y rubber, through condenser tubes by air or water pressure and to thus rub off and remove a considerable part of the dirt within the tubes, my invention ,disclosed herein has increased the efficiency of the operatihnby approximately 40 per cent in quantity, removing also that part of the coating closest tothe tubes left by the previously existing slugs and securing contact of the contents of the tube with the metal of'the tube itself which much further increases the efficiency of heat transfer. I

Referring to the forms illustrated, in exgaging surface.

' and except for the tapering edges 11 and 12 are also I so as to wipe them clean.

Whichever the direction of movement of the aperture it makes no difference in this formthe leading edge, preferabl 9, performs some scraping functlon but 1'. e firmest engagement is made by the trailing edge, in that case 10. The outer end faces are annular at '13. The helpful, according .to the direction of movement. Both ends are cupped at 14 so that the fluid pressure may be 'efi'ective on the rear to press the rear portion Y of the corresponding cylindrical rim 8 or 8 outwardly against the interiors of the tubes.

The cylindrical rim 8 gives a long tube en- This fact and the stiffening of the tube by the fillet at 7 would be sufiicient to prevent turning of the end cup at 14 wrong side out. They very effectively maintain the shape of the cup for the purpose engaged.

7 he aperture through the slu is preferably tapered so as to produce an eective nozzle. In the illustration the larger end of the aperture is shown at the rear which will project the discharge a considerable distance into the tube before the fluid spreads suificiently to engage the interior walls of the tube. This extends the distance between the slug and the point where the fluid makes impact with the interior walls of the tube but produces the best results as it considerably increases the velocit? of the fluid and the consequent cleansing ct of the jet.

On the other hand if theslug be passed through the tube with the smaller end of the tapered opening at the rear, along with lower velocity of fluid through the nozzle is obtained a quicker distrlbution of the fluid against the walls of the tube, causing engagement of the fluid with the tube walls closer to the advancing slug.

In use, the slug is inserted within one end of a tube such as 17 to be cleaned and the nozzle by which the driving fluid pressure is applied, usually air or water, is pressed against or within the end of the tube to apply the pressure back of the slug. The slug is expanded bodily (if the larger end of the tapered openin be at the rear) but particularly at the cuppe rear end by reason of the pressure against the interior walls.

As the slug is" moved through the tube by fluid pressure at the rear 9. portion of the fluid supplied under pressure passes through the aperture or nozzle through the body of the slug and impinges (at a distance depending upon the predetermined character of nozzle formed) against the interior of the tube,

' loosening and removing a considerable part of the dirt within the tube before the slug reaches it.

Where the dirt is dry it may be elfectiveliy moistened and loosened in this way in a Vance of the slug by driving the slug by water pressure.

As will be seen not only does the slug perform the function of prior imperforate slugs used in this art of wiping the interior surface of the tube but it provides an advancing nozzle by which successive sections of the tube ahead of the plug are preliminarily cleaned and may preliminarily also be moistened, re-

ducing the amount of work left for the slug.v

The aperturing of the slug not only provides an advancing jet nozzle and allows the slu to be swelled outwardly in its entirety, assisting the cu ping in securing maximum pressure of the s ug against the interior walls of the tubes, but it also provides additional resilience for radial compression of the slug so that it may pass obstacles or to permit use of the same slug in a larger range of tube diameters.

When air pressure is used to drive the slug through the tubes, the aperturing of the slug secures a further advantage, in that if the tube ahead of the slug becomes clo ged, the slug automatically will be driven back and out of the tube as soon as the air pipe is removed, thus giving direct access to the clogged portion of the tube.

As a reason for this, when a tube becomes clogged ahead of the slug there is almost immediately full air pressure ahead of'the slug, after which there is no further tendency toward driving the plug into the obstruction, air pressure on both sides of the slug being the same. When the air pipe is taken away, suddenly releasin the pressure back of the slu the air trapped in front of the slug suddenl y expands driving the slug ahead of it out of the tube, the aperture through the slug being too small to instantly release the pressure.

In practice I have secured excellent results with quite small apertures, as one fifth of the diameter of the slu with which the nozzle is very effective and t e driving pressure is not noticeably reduced.

While in practice I much prefer to aperture the slug so as to secure the double advantage of the ex ansion to close contact with the tube an throu h the slug, it may under certain conditions e desired to avoid the blast of fluid through the slug, and I show in Figures 3 and 4 a form adapted to meet this condition, the slug shown being like that of Fi res 1 and 2 with the exception that while t e slug is internally hollowed at 15' from the rear end to give expansion to close contact with the tube, this internal hollow does not ass through the slu and the blast through the slug is thus avoided. This form may be used substantially the same as that of Figures 1 and 2, and like that form may be sent through the tube with either end forward, the mere cupping of the end being sufficient to give expansion to close contact with the tube, though of the cleaning blast ing.

front and expansion to close contact with the tubes.

'When more than one aperture or nozzle is to be used I et the best results by forming the nozzles rom a common central open- In the form of Figures 6 and 7, there are a plurality of inclined nozzles 18 from the internal hollow 15 spaced circumferentially about the plug and adapted todischarge a plurality of cleaning blasts against the walls of the tubes at an angle sufliciently stee to enetrate the dirt and loosen it more ully om the tube walls ahead of the slug.

In the form shown in Figures 8 and 9 the slug is of the same character as that shown in igure 1 but the rear rim 8 is provided with inset metal scraping surfaces in the form of wire loops 20 anchored within the body of the slug by prongs 21. The loops are shown as arranged in annular rows which overlap, the central portions of the loops of one row spanning the ends of the loops of the next.

In Figure 10 the same eneral form is shown but lates 20' are use instead.

In both orms the metal scraping surfaces are pressed outwardly against the interior of the tube which is bein cleaned by the pressure of the drivin uid. The metal scrapers perform their %unction without interference with the wiping action of the adjoining rubber.

The directions of motion of the different 3. A rubber slug for use in cleansing condenser tubes by passage through the tubes and scraping engagement with their walls, having a concave rear end anda central longitudinal passage to allow flow of fluid throu h the slug.

4. slug for cleaning condenser tubes, comprising an elongated body of rubber having approximately the same diameter at both ends, said plu bein of reduced-diameter between the an s an having a central aperture flaring at the rear as compared with the front end. v

5. A tube for cleanin condenser pipes comprising a rubber b0 y centrally apertured, the aperture tapering toward its front 7 end to permit flow of fluid through the bod and to converge the lines of such flow.

M WILLIAM F. OBERHUBER.

slugs are indicated by the arrows on the figures.

Other forms of my invention will occur to those skilled in the art which secure all or a art of the benefit of the invention but which depart from it according to the whim of the designer or his desire to avoid the use of the forms illustrated by me; and it is my intention to include herein all such other forms that may come within the reasonable spirit and scope of m claims.

' Having thus descri ed my invention, what I claim as new and desire to secure by Letters Patent is:

1. A rubber slug for use in cleaning condenser tubes by passage through the tubes and scraping engagement with their walls a having a free central longitudinal passage to allow pressure discharge of the fluld 1 through it.

2. A rubber slug for use in cleansing condenser tubes by passage through the tubes and scraping engagment with their walls, provided with a central tapered passage lengthwise of the slug to permit and direct fluid passing through it. 

